It is well known that obesity and a poor diet leads to an increased risk of stroke and cardiovascular disease, but the effect of acute changes in diet remain largely unknown.
A research group from the University of Manchester have established that high-fat ‘binge-eating’ can significantly worsen the damage caused by stroke. The group fed mice a high-fat diet for 3-days prior to inducing a stroke, which caused an increased detrimental outcome of up to 48%.
Chronic vs Acute
In contrast to a chronic high-fat diet, the mice in this study didn’t have the archetypal symptoms of the diet; without having the physical signs of weight gain, increase in fatty tissue or inflammatory markers in or outside of the brain.
Lead author Michael Haley explained the rationale for instigating these experiments;
“Although people have looked at long term high-fat diets and their relationship to stroke outcome, no one has ever really looked at the effect of short term high-fat diets”.
On a more molecular level, the group discovered that the acute high-fat diet dramatically altered the way the body deals with glucose, increasing levels of glucose in blood plasma and reducing tolerance to glucose. They found that the acute high-fat diet altered the expression of a key glucose transporter in the brain (GLUT-1), which will have subsequent effects on the glucose balance within the body.
“We know that glucose homeostasis in the body is important when looking at stroke outcome and recovery. It’s well documented that people with diabetes have an increased risk of stroke and high glucose is associated with worse outcome,”
Typical ‘Western-style diets’ are commonly high in fats and sugars, which can lead to cardiovascular and neurovascular diseases like heart attack or stroke. Previous studies have also established the effect of high-fat diets on neural function, with impaired learning and memory being a consequence in both animals and humans.
This may tie the research into Alzheimer’s disease studies, where diabetes is a risk factor for onset of the disease. Potentially exacerbating and increasing onset and progression through alterations in glucose metabolism.
Although the current focus of the group lies outside these acute ‘binge-eating’ studies, Catherine Lawrence and Michael Haley were able to offer what the next steps would be for continuing this research:
“It would be interesting to see if an acute high-sugar diet would have the same outcome, as well as probing the cut off for when diet has an effect. Additionally looking into the specific molecular mechanisms which alter glucose homeostasis and metabolism from this type of diet would help pin-point the relationship between glucose metabolism and worsened outcome”.
Although the results of this research elucidate the role of diet in stroke damage severity, it is hard to implement the findings to improve patient outcome, as it is not possible to predict when a stroke is going to occur. This is summarised nicely by one of the papers authors, Siddarth Krishnan, who was talking about the study’s findings,
“It shows that worsened stroke outcome is not reliant on just being obese, but diet has a large influence. Having a balanced diet is extremely important; it’s as simple as that”.